Answer:
Vf = 73.4 m/s
Explanation:
This is the case of vertical motion where we have to find the final velocity of the penny when it hits the ground. We can use 3rd equation of motion to find the final velocity:
2gh = Vf² - Vi²
where,
g = 9.8 m/s²
h = height = 275 m
Vf = Final Velocity = ?
Vi = Initial Velocity = 0 m/s
Therefore,
2(9.8 m/s²)(275 m) = Vf² - (0 m/s)²
Vf = √5390 m²/s²
<u>Vf = 73.4 m/s</u>
Answer: The angle between the wire segment and the magnetic field 66.42°
Explanation:
Please see the attachment below
Answer:

Explanation:
If the collision is elastic and exactly head-on, then we can use the law of momentum conservation for the motion of the 2 balls
Before the collision

After the collision

So using the law of momentum conservation


We can solve for the speed of ball 1 post collision in terms of others:

Their kinetic energy is also conserved before and after collision


From here we can plug in 






<u>Correct Question:</u>
Calculate the distance (in km) charlie runs if he maintains an average speed of 8 km/hr for 1 hour
<u>Answer:</u>
The total distance covered by Charlie is 8 km in 1 hour.
<u>Explanation:</u>
The average velocity as given in the question is,
v = 8 km/hr
Total time taken,

As we know the formula to evaluate the total distance d when the average velocity and time is given;




Hence, the total distance covered by Charlie in 1 hour will be 8 km.
Answer:

Explanation:
Given:
- mass of car,

- distance of skidding after the application of brakes,

- coefficient of kinetic friction,

<u>So, the energy dissipated during the skidding of car:</u>
<em>Frictional force:</em>

where N = normal reaction by ground on the car


<em>Now from the work-energy equivalence:</em>


is the dissipated energy.