Advertisements
Advertisements
प्रश्न
How long will a stone take to fall to the ground from the top of a building 80 m high
Advertisements
उत्तर
Height, s = 80m
g = 10 m/s2
Using the second equation of motion,
S = ut + (1/2) gt2
Or, 80 = 0+ (1/2) (10) (t) 2
Or, (t) 2 = 16
Or, t = 4s
APPEARS IN
संबंधित प्रश्न
A batsman deflects a ball by an angle of 45° without changing its initial speed which is equal to 54 km/h. What is the impulse imparted to the ball? (Mass of the ball is 0.15 kg.)
Explain why a cricketer moves his hands backwards while holding a catch.
The rear side of a truck is open and a box of 40 kg mass is placed 5 m away from the open end as shown in Figure. The coefficient of friction between the box and the surface below it is 0.15. On a straight road, the truck starts from rest and accelerates with 2 m s–2. At what distance from the starting point does the box fall off the truck? (Ignore the size of the box).
Two objects A and B are thrown upward simultaneously with the same speed. The mass of A is greater than that of B. Suppose the air exerts a constant and equal force of resistance on the two bodies.
Find the acceleration of the blocks A and B in the three situations shown in the following figure.
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 magnitude of the force
The INCORRECT statement about Newton's second law of motion is
A body of mass 2 kg travels according to the law x(t) = pt + qt2 + rt3 where p = 3 ms−1, q = 4 ms−2 and r = 5 ms−3. The force acting on the body at t = 2 seconds is ______.
Why is catching a slow-moving ball easier than catching a fast-moving ball?
How does moving your hand backward while catching a cricket ball reduce pain?
