Advertisements
Advertisements
Question
A ball is thrown vertically downward with an initial velocity of 10 m/s. What is its speed 1 s later and 2 s later?
Advertisements
Solution
Initial speed of ball = 10 ms-1.
Acceleration due to gravity on ball = - 9.8 ms-2
We know that from first equation of motion
v= u + gt.
After 1 sec
v= 10 - 9.8 X1
v= 0.2 ms-1
so velocity after 1 sec would be 0.2 ms-1.
Velocity after 2 seconds
v= 10 - 9.8X2 = 10 - 19.6 = -9.6 ms-1.
Here negative sign shows that velocity is in downward direction and magnitude is 9.6 ms-1.
APPEARS IN
RELATED QUESTIONS
Two bodies of masses 10 kg and 20 kg respectively kept on a smooth, horizontal surface are tied to the ends of a light string. A horizontal force F = 600 N is applied to
- A,
- B along the direction of string. What is the tension in the string in each case?
A car accelerates on a horizontal road due to the force exerted by.
Calculate the tension in the string shown in the following figure. The pulley and the string are light and all the surfaces are frictionless. Take g = 10 m/s2.
Find the acceleration of the block of mass M in the situation shown in the following figure. All the surfaces are frictionless and the pulleys and the string are light.
Find the acceleration of the 500 g block in the following figure.
A block is kept on the floor of an elevator at rest. The elevator starts descending with an acceleration of 12 m/s2. Find the displacement of the block during the first 0.2 s after the start. Take g = 10 m/s2.
Two bodies A and B of same mass are moving with velocities v and 2v, respectively. Compare their (i) inertia and (ii) momentum.
A force acts for 10 s on a stationary body of mass 100 kg, after which the force ceases to act. The body moves through a distance of 100 m in the next 5 s. Calculate: The velocity acquired by the body.
How long will a stone take to fall to the ground from the top of a building 80 m high
A pebble is dropped freely in a well from its top. It takes 20 s for the pebble to reach the water surface in the well. Taking g = 10 m s-2 and speed of sound = 330 m s-1. Find : The depth of water surface
