Answer:
Applications of electromagnetic waves
Explanation:
"Hot" objects in space emit UV radiation as well. X-ray: A dentist uses X-rays to image your teeth, and airport security uses them to see through your bag. Hot gases in the Universe also emit X-rays. Gamma ray: Doctors use gamma-ray imaging to see inside your body.
Complete Question:
One simple model for a person running the 100 m dash is to assume the sprinter runs with constant acceleration until reaching top speed, then maintains that speed through the finish line. If a sprinter reaches his top speed of 11.5 m/s in 2.24 s, what will be his total time?
Answer:
total time = 6.24 s
Explanation:
Using the equation of motion:
v = u + at
initial speed, u = 0 m/s
v = 11.5 m/s
t = 2.24 s
11.5 = 0 + 2.24a
a = 11.5/2.24
a = 5.13 m/s²
For the total time spent by the sprinter:
s = ut + 0.5at²
100 = 0.5 * 5.13 * t²
t² = 100/2.567
t² = 38.957
t = √38.957
t = 6.24 s
Answer:
option b
Explanation:
the heavier one will have twice the kinetic energy of the lighter one
Given,
The momentum of the object A before the collision, p₁ =80 Ns
The momentum of the object B before the collision, p₂=-30 Ns
Given that the objects stick together after the collision.
From the law of conservation of momentum, the total momentum of a system should always remain the same. Thus the total momentum of the objects before the collision must be equal to the total momentum of the objects after the collision.
Thus,
Where p is the total momentum of the system at any instant of time.
On substituting the known values,
Therefore the total momentum of the system is 50 Ns
Thus the momentum of the object AB after the collision is 50 Ns
