A scalar is a quantity that is fully described by a magnitude only. It is described by just a single number. Some examples of scalar quantities include speed, volume, mass, temperature, power, energy, and time. A vector is a quantity that has both a magnitude and a direction.
I hope this helps you.
Answer:
Explanation:
Horizontal displacement
x = 120 t
Vertical position
y = 3610 - 4.9 t²
y = 0 for the ground
0 = 3610 - 4.9 t²
t = 27.14 s
This is the time it will take to reach the ground .
During this period , horizontal displacement
x = 120 x 27.14 m
= 3256.8 m
So packet should be released 3256.8 m before the target.
Answer:
F₁ = 4 F₀
Explanation:
The force applied on the string by the ball attached to it, while in circular motion will be equal to the centripetal force. Therefore, at time t₀, the force on ball F₀ is given as:
F₀ = mv₀²/r --------------- equation (1)
where,
F₀ = Force on string at t₀
m = mass of ball
v₀ = speed of ball at t₀
r = radius of circular path
Now, at time t₁:
v₁ = 2v₀
F₁ = mv₁²/r
F₁ = m(2v₀)²/r
F₁ = 4 mv₀²/r
using equation (1):
<u>F₁ = 4 F₀</u>
Answer:
Acceleration is the change in velocity over the change in time = Δv/Δt. To do these problems, you need to find out how much the speed changed and over what period of time it changed.
Snail 1 changes from 4 cm/min to 7 cm/min in 3 minutes. Subtract the starting velocity (4 cm/min) from the ending velocity (7 cm/min) then divide by the time (3 min):
Snail 1 = (7 cm/min. - 4 cm/min)/(3 minutes) = ? (remember to put down the units)
Snail 2 changed from 7 cm/min. down to 1 cm/min. in 3 minutes
Snail 2 = (1 cm/min. - 7 cm/min.)/(3 min.) = ? (note that the acceleration is negative when you slow down)
I hope this helps you
Answer: False
Explanation:
Relative to the concept of radiations, a black body is an object capable of absorbing any form of electromagnetic radiation irrespective of its frequency or angle of incidence when incident on such object.
However, the same cannot be said about real bodies as real bodies are those which reflect all rays incident on them completely and uniformly in all directions.
One very important characteristic of black bodies is that they are ideal emmiters.
The concept of emmisivity is brought about by the existence of real bodies .
This is due to the fact that they are only able to emit radiation at a fraction of the black body energy levels.
Please note that by convention, the emmisivity of a real body is always less thaan 1.
As such they are not able to emit as much radiation as a black body at the same temperature.
