Solve the following problems: (3pts each) 1. Calculate the power of a car brake that it is capable of doing 40000J of work in 5 s when stopping the car.
2. Kram can lift a 40.0-kg sack of rice at a height of 0.10 m 15 times in 1 minute. What is Kram’s power output?
3. How much work is done in lifting an object that weighs 250N to a height of 4m?
4. How much power is exerted if the 250N object is lifted to a height 4m in 4s?
5. While doing a chin-up, Gina lifts her 45.0-kg body to a height of 0.25 meters in 5 seconds. What is the power delivered by Gina's biceps?

Consider a hydrogen atom in the ground state. what is the energy of its electron? =e= jj now consider an excited‑state hydrogen atom. what is the energy of the electron in the =5n=5 level? =e5= j

With physics question #5? for any !

Learning goal: to understand newton's 1st law. newton's principia states this first law of motion: an object subject to no net force maintains its state of motion, either at rest or at constant speed in a right line. this law may be restated as follows: if the sum of all forces acting on an object is zero, then the acceleration of that object is zero. mathematically this is just a special case of the 2nd law of motion, f⃗ =ma⃗ , when f⃗ =0. when studying newtonian mechanics, it is best to remember the 1st law in two ways: if the net force (i.e., sum of all forces) acting on an object is zero, the object will keep moving with constant velocity (which may be zero). if an object is moving with constant velocity, that is, with zero acceleration, then the net force acting on that object must be zero. complete the following sentences to see if you can apply these ideas. part a if a car is moving to the left with constant velocity, one can conclude that