Answer: What is the difference of physical quanity and a unit?
Explanation: If you are working science or math problems, the answer to this question is that quantity is the amount or numerical value, while the unit is the measurement. For example, if a sample contains 453 grams, the quantity is 453 while the unit is grams.
Answer:
1.35 kJ
Explanation:
KE = ½mv² = ½ × 0.030 kg × (300 m·s⁻¹)² = 1350 J = 1.35 kJ
Answer:
Explanation:
The forces exerted by each mass is best understood in terms of their momentum.
Momentum is a sort of compelling force or impulse. It is given as:
Momentum = mass x velocity
Let us consider the momentum of the balls;
Substance C;
Mass = 1kg
Velocity = 5m/s
Momentum of C = 1 x 5 = 5kgm/s
Substance D:
Mass = 100kg
Velocity = 5m/s
Momentum of D = 100kg x 5m/s = 500kgm/s
Body D has a higher momentum compared to Body C. This suggests that body D will exert a higher force than C when they collide.
The higher the momentum, the more the force of impact it has.
Answer:

Explanation:
Let say the empty wagon has mass "M"
now by newton's II Law we will have

now it is given that empty wagon is pulled with acceleration 1.4 m/s/s
now we will have

now a child of mass three times the mass of wagon is sitting on the empty wagon
so here we have


so we have

Answer:
Explanation:
a ) The earth rotates by 2π radian in 24 x 60 x 60 s
so angular speed ( w ) = 2π / (24 x 60 x 60) = 7.268 x 10⁻⁵ rad / s
b ) Linear speed of city of Arlington ( v ) = w r = w R Cosλ where R is radius of the earth and λ is latitude .
v = 7.268 x 10⁻⁵ x 6.371 x 10⁶ cos 32.7357
389.5 m /s
acceleration = w² r = w² R Cos 32.7357
= (7.268 x 10⁻⁵ )² x 6.371 x 10⁶ x cos 32.7357
=283.08 x 10⁻⁴ m/s²
c) velocity ratio =
w r /w R =
R cos 32.73/ R
= Cos 32.73
= 0.84 .