Answer:
v = 10 m/s
Explanation:
Given that,
Distance covered by a sprinter, d = 100 m
Time taken by him to reach the finish line, t = 10 s
We need to find his average velocity. We know that velocity is equal to the distance covered divided by time taken. So,
v = d/t

Hence, his average velocity is 10 m/s.
Answer
given,
mass of the ball = 3 kg
swing in vertical circle with radius = 2 m
work done by the gravity = ?
work done by the tension = ?
Work done by the gravity = - m g Δh
Δ h = 2 + 2 = 4 m
Work done by the gravity =
= -117.6 J
work done by gravity is equal to -117.6 J
Work done by tension will be equal to zero.
Zero because tension is always perpendicular to velocity
work done by tension is equal to 0 J
Answer:
b) Nothing will happen, the sea saw will still be balanced.
Explanation:
b) Nothing will happen, the sea saw will still be balanced.
Reason:-
When two kids are balanced, the sum of torques on the seesaw will be zero.
if each kid, reduces their distances by half, then the torque of each kid will be half and the sum of torque of each on the seesaw will be zero.
Therefore the seesaw is balanced
Answer:
0.799 m/s if air resistance is negligible.
Explanation:
For how long is the ball in the air?
Acceleration is constant. The change in the ball's height
depends on the square of the time:
,
where
is the change in the ball's height.
is the acceleration due to gravity.
is the time for which the ball is in the air.
is the initial vertical velocity of the ball.
- The height of the ball decreases, so this value should be the opposite of the height of the table relative to the ground.
. - Gravity pulls objects toward the earth, so
is also negative.
near the surface of the earth. - Assume that the table is flat. The vertical velocity of the ball will be zero until it falls off the edge. As a result,
.
Solve for
.
;
;
;
.
What's the initial horizontal velocity of the ball?
- Horizontal displacement of the ball:
; - Time taken:

Assume that air resistance is negligible. Only gravity is acting on the ball when it falls from the tabletop. The horizontal velocity of the ball will not change while the ball is in the air. In other words, the ball will move away from the table at the same speed at which it rolls towards the edge.
.
Both values from the question come with 3 significant figures. Keep more significant figures than that during the calculation and round the final result to the same number of significant figures.