How large would a coin be with diameter of 3/4 in appear through a 5x lens

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.

Which type of energy would have nothing to do with ironing clothes? a. heat b. chemical c. electrical d. mechanical

To practice problem-solving strategy 10.1 for energy conservation problems. a sled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slides a distance d1 down the slope and then covers the distance d2 along the horizontal terrain before stopping. find the coefficient of kinetic friction μk between the sled and the ground, assuming that it is constant throughout the trip.