Physics Answers

7. A 25 kg child slides down a 6.5 m playground slide that makes an angle of 20o with horizontal. The coefficient of kinetic friction between slide and child is 0.10.

Find the following:

a. What kind of energy is present on the child at the top of the slide? At the bottom of the slide?

b. How much potential energy does the child have?

c. How much kinetic energy does the child have?

d. How much energy is transferred to thermal energy?

e. If she starts at the top with A SPEED OF 0.50 m/s, what is her speed at the bottom?

A 200 g object is whirled in a horizontal circle with a cord of radius 1.2 m at 3rev/s. The work done in doing this is.

Your mother asked you to do the laundry for the day. She reminded you that some of the

clothes are used by your father in the farm. The clothes are soiled and greasy. She even

instructed you to save resources and energy because we are in a state of pandemic due

to Covid-19. As a student of Physical Science and with the knowledge on the effect of

intermolecular forces on substances, how are you going to perform the task in such a way

that energy is not wasted?

Using uncertainty principle show that an electron can't stay inside the nucleus . Radius of nucleas =5 ×10^-15

A car starts from the rest covers a distanc 500m while accelerating uniformly at 10m/s2.

A cube of mass 10kg is at rest on a horizontal surface when it is subjected to a horizontal for P that varies with time t as P=20t. If the static and kinetic coefficients of friction are both 0.4, calculate the velocity of the cube after 5s.

An escalator is used to move 15 passengers every minute from the first floor of a department store to the second. The second floor is located 6 meters above the first floor. The average passenger's mass is 52 kg. Determine the power requirement of the escalator in order to move this number of passengers in this amount of time. 

What is the Kinetic Energy of a 1300 kg object that is moving with a speed of 30 m/s? *

A tennis ball is traveling at 40 m/s and has a kinetic energy of 80 J. Calculate the mass of the tennis ball. *

 Michael (mass of approximately 60 kg) does push-ups by applying a force to elevate its center-of-mass by 20 cm in order to do 850 Joule of work. If the man does all this work in 5 seconds, then determine its power.