I think you almost got it.
At the top, the velocity only has horizontal component, so v=12 m/s is v_x, which is v*cos(theta), because v_x is constant, so the same when it was launched or now.
With the value of the initial speed (28 m/s, which is the total speed), you can set
v_x = v * cos( theta ) ---> 12 = 28*cos(theta) --> cos(theta)=12/28=3/7
or theta = 64.62 deg, it is D. Think about it. I hope you see it.
Answer: false.
Explanation:
Doppler effect is caused to the relative motion of the source of light/sound with respect to the observer.
If the source is moving towards you, you will perceive the frequency to be larger (also called a blue shift), while if the wave is moving away, you will perceive the frequency to be smaller (also called a red shift).
Then the statement:
"Doppler effect is caused by sound or light wave being pushed together and spread apart due to motion."
Is false
Answer:
The car exerts a force on the truck which is c.) 6000 N.
Explanation:
If the truck exerts a force of 6000 N on the car then according to Newton's Third Law of Motion that every action has an equal and opposite reaction we can say that the force exerted by the car on the truck is 6000 N.
The only reason the truck is able to move the car is because of the frictional forces. That is frictional force of the trucks tires on the surface of the road and the frictional forces of the cars tire on the surface of the road, and since these forces are not equal this therefore gives rise to motion.
Answer:
it should be B let me know if i am wrong
Explanation:
Answer:
44 N/m
Explanation:
The extension, e, of the spring = 2.9 m - 1.4 m = 1.5 m
The work needed to stretch a spring by <em>e</em> is given by

where <em>k</em> is spring constant.

Using the appropriate values,
