An athlete does one push-up period in the process, she moves half of her body weight, 250 N, a distance of 20 cm, this distance
1 answer:
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A billiard ball collides with a stationary identical billiard ball to make it move. If the collision is perfectly elastic, the first ball comes to rest after collision.
<h3>Why does the first ball comes to rest after collision ?</h3>Let m be the mass of the two identical balls.
u1 = velocity before the collision of ball 1
u2 = 0 = velocity of second ball that is at rest
v1 and v2 are the velocities of the balls after the collision.
From the conservation of momentum,
∴ mu1 + mu2 = mv1 + mv2
∴ mu1 = mv1 + mv2
∴ u1 = v1 + v2
In an elastic collision, the kinetic energy of the system before and after collision remains same.
∴
∴
∴ ₁
₂ = 0
- It is impossible for the mass to be zero.
- Because the second ball moves, velocity v2 cannot be zero.
- As a result, the velocity of the first ball, v1, is zero, indicating that it comes to rest after collision.
An elastic collision is a collision between two bodies in which the total kinetic energy of the two bodies remains constant. There is no net transfer of kinetic energy into other forms such as heat, noise, or potential energy in an ideal, fully elastic collision.
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The new gravitation force at the new location is 40 N
Explanation:
The weight of the astronaut is given by the equation
(1)
where
m is the mass of the astronaut
g is the acceleration of gravity
The acceleration of gravity at a certain distance from the centre of the Earth is given by
where G is the gravitational constant and M is the Earth's mass. So we can rewrite eq.(1) as
When the astronaut is on the Earth's surface, (where R is the Earth's radius), so his weight is
Later, he moves to another location where his distance from the Earth's surface is 3 times the previous distance, so the new distance from the Earth's centre is
Therefore, the new weight is
Which means that his weight has decreased by a factor 16: therefore, the new weight is
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Answer:
16.6 kJ/°C
Explanation:
given,
Amount of heat absorbed = 45 kJ
initial temperature, T₁ = 25.5°C
final temperature, T₂ = 28.2°C
change in temperature = T₂ - T₁
= 28.2 - 25.5 = 2.7° C
Heat capacity of the object is equal to 16.6 kJ/°C