1) v=u+at
2) S= ut+ at²/2
3) v²- u²= 2aS
B) When u is initial velocity, v is final velocity g is acceleration due to gravity S is distance covered and t is the time in second then:
1) v=u+gt
2) S= ut+ gt²/2
3) v²- u²= 2gS
1) a motorbike initially at rest, picks up a velocity of 72km/hr over a distance of 40m. calculate a) acceleration
b) time in which it picks up the above velocity. 5m/s², 4s.
2) a cyclist driving at 5m/s, pick up a velocity of 10m/s, over a distance of 50m, calculate
a) acceleration
b) time in which the cyclist picks up the above velocity. 0.75m/s²,6.67s
3) aeroplane lands at 216km/hr and stops after covering a Runway of 2km. Calculate
a) acceleration
b) time in which it comes to rest.
- 0.90m/s², 66.67s
4) a truck running at 90km/hr is brought to rest over a distance of 25 m. calculate
a) the retardation and time for which brakes are applied. - 12.5m/s², 2s
5) A racing car, initially at rest, picks up a velocity of 180km/hr in 4.5s. calculate
a) acceleration. 11.11m/s²
b) distance covered by car. 112.5m.
6) A motor bike running at 5m/s, picks up a velocity of 30m/s in 5sec. calculate
A) acceleration
B) distance Covered during acceleration. 5m/s², 87.5m
7) A motor bike running at 90 km/hr is slowed down to 18km/hr in 2.5s. Calculate
A) Acceleration. -8 m/s²
B) distance covered during the action of slowing down. 37.5m
8) A cyclist driving the 36 km/hr, stops his mount in 2 s, by the application of breaks calculate
A) the the retardation. -5m/s²,
B) distance covered during the action of application of brakes. 10m.
9) a motorbike running at 90km/hr is slowed down down to 54km/hr by the application of brakes, over distance of 40m. if the brakes are applied with same force. calculate
A) Total distance travelled by the bike. 62.5m
B) the total time in a which bike comes to rest. 5s
10) A motor car slows down from 70km/hr to from 36 km/hr over a distance of 25m. if the brakes are applied with the same force, calculate a) distance travelled by the car b) total time in which the car comes to rest. 33.33m, 3.33s
11) A packet is dropped from a stationary helicopter, hovering at a height 'h' from ground level, reaches the ground in 12s. calculate
A) the value of 'h'
B) final velocity of packet on reaching ground level
(g=9.8 m/s²). 705.6m, 117.6m/s
12) a boy drops a stone from Cliff. it reaches the ground in 8s. calculate
A) height of cliff
B) final velocity of stone (taking g= 9.8m/s²). 313.6m, 78.4m/s
13) A stone is thrown vertically upwards, takes 3s to attain maximum height Calculate
A) initial velocity. 29.4m/s
B) maximum height attained by stone.(g= 9.8m/s²). 44.1m
14) A stone is thrown vertically upwards, takes 4s to return to the thrower. Calculate
A) initial velocity. 19.6 m/s
B) final velocity of stone on reaching ground level.
C) de-acceleration produced by mud (g=9.8m/s²).
16) A packet dropped from a helicopter reaches the water level of a river in 7.5s and then travels for 4m within the water, before coming to rest. calculate
A) height of helicopter above the level of water.
B) final velocity of packet, before hitting water
C) retardation offered by water (g= 10m/s²). 281.25,75,703.125
17) A spaceship is moving in space with a velocity of 50km/s. Its engine fire for 10 second. such that it's velocity increases to 60km/s. calculate the total distance travelled by the spaceship in half minute from the the time of firing its engines
550km, 1750km.
18) A spaceship is moving in space with the velocity of
60km/s. It fires its retro-engines for 20s and the velocity reduced to 55km/s. calculate the distance travelled by spaceship in 40s. from the time of firing retro- engines. 1150km, 2250km.
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1) An object cover a distance in S in time as follows.
S (metres): 0 4 10 10 8 5 0
t (seconds):0 2 5 10 12 15 20 plot a graph, taking t on x-axis and S on y-axis. Determine displacement of object at a time
A) 7 s. 10m
B) 13 s. . 7m
2) Displacement: 0 4 8 12 16 20
Time:. 0 1 2 3 4 5
From the displacement-time table given above draw a graph choosing a suitable scale. From the graph calculate
A) Average velocity. 4 m/s
B) displacement between 1.5s and 3.5s. . 8m
3)
Displacement: 3 6 9 12 12 12 6 0
Time:. 0 1 2 3 4 5 6 7
From the displacement-time table given above draw a graph choosing a suitable scale. From the graph calculate
A) Average velocity between 0-3 s. 3m/s
B) Average velocity 3s-5s. 0 m/s
C) Average velocity between 5s--7s. . -5m/s.
4) A car travels at a uniform velocity of 25m/s for 5s. The brakes are then applied and comes to rest with a uniform retardation in further 10s. Draw a graph of velocity vs. time. From the graph find out distance which the car travels, after brakes are applied. Calculate the value of retardation. 125m, 2.5 m/s
5) A racing car moving with a velocity of 50m/s. On applying brakes, it uniformly retards and comes to rest in 20s. Draw a velocity-time graph and calculate:
A) Acceleration. -2.5 m/s²
B) Distance covered by car. 500m
6)
Velocity in m/s): 20 20 10 20 0
Time in(sec): 0 5 7 10 15
The table above shows the velocity of a motorbike at various Intervals of time.
A) Plot the velocity-time graph
B) calculate de-acceleration between 5s--7s. . -5 m/s²
C) calculate acceleration between 7s and 10s. . 3.33m/s²
D) Calculate de-acceleration between 10s and 15s. -5m/s²
E) Total distance travelled by motorbike. . 225m
F) Average velocity of motorbike. 15m/s
7) A train starting from rest, picks up a speed of 20m/s in 200s. It continues to move at the same rate for the next 500s and then brought to rest in another 100s.
A) plot a speed-time graph.
B) From the graph calculate
I) uniform rate of acceleration. 0.1 m/s²
ii) uniform rate of retardation. -0.2 m/s
iii) Total distance covered before stopping. 13000m
iv) average speed. 16.25m/s
8) A ball is thrown vertically upwards, returns back to the thrower in 6s. Assuming there is no air friction, plot a velocity-time graph. From the graph calculate:
A) De-acceleration. -10m/s²
B) acceleration. 10m/s²
C) Total distance covered by ball. 90m
D) Average velocity. 15m/s
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