The world record for pole vaulting is 6.15 m. If the pole vaulter's gravitational potential energy is 4942 J, what is his mass?
1 answer:
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Answer:
The force exerted by the ball on the bat has a magnitude of 100 N and its direction is exactly opposite to that of the force exerted by the bat on the ball.
Explanation:
Recall that Newton's third law tells us that : "For every action, there is an equal and opposite reaction."
Therefore if the bat acts on the ball with a force of 100 N, the ball acts on the bat with a similar magnitude of force (100 N) but direction opposite to the original force.
Answer:
Explanation:
The electric flux through a certain surface is given by (for a uniform field):
where:
E is the magnitude of the electric field
A is the area of the surface
is the angle between the direction of the field and of the normal to the surface
In this problem, we have:
is the electric field
L = 2.0 m is the side of the sheet, so the area is
, since the electric field is perpendicular to the surface
Therefore, the electric flux is
Answer:
The skater covers a distance of <u>15 m</u> before stopping.
Explanation:
Let the distance traveled before stopping be 'd' m.
Given:
Mass of the skater (m) = 90 kg
Initial velocity of the skater (u) = 12.0 m/s
Final velocity of the skater (v) = 0 m/s (Stops finally)
Coefficient of kinetic friction (μ) = 0.490
Acceleration due to gravity (g) = 9.8 m/s²
Now, we know that, from work-energy theorem, the work done by the net force on a body is equal to the change in its kinetic energy.
Here, the net force acting on the skater is only frictional force which acts in the direction opposite to motion.
Frictional force is given as:
Where, 'N' is the normal force acting on the skater. As there is no vertical motion,
∴
Now, work done by friction is a negative work as friction and displacement are in opposite direction and is given as:
Now, change in kinetic energy is given as:
Therefore, from work-energy theorem,
Hence, the skater covers a distance of 15 m before stopping.