Answer:
a. F = 245 Newton.
b. Workdone = 392 Joules.
c. Power = 196 Watts
Explanation:
Given the following data;
Mass = 25kg
Distance = 1.6m
Time = 2secs
a. To find the force needed to lift the mass (in N );
Force = mass * acceleration
We know that acceleration due to gravity is equal to 9.8
F = 25*9.8
F = 245N
b. To find the work done by the student (in J);
Workdone = force * distance
Workdone = 245 * 1.6
Workdone = 392 Joules.
c. To find the power exerted by the student (in W);
Power = workdone/time
Power = 392/2
Power = 196 Watts.
Answer:
b- a bicycle sitting on the ground
Explanation:
'Static' means it's not moving.
So, only the answer listed as "a bicycle sitting on the ground" corresponds to that condition.
All others possible answers describe something that is moving (an apple falling, a motorcycle accelerating, a car moving at a constant speed). Even if they are going at a constant speed, they are moving, so not static.
Answer:
minimum angle is 128.69°
Explanation:
given data
player velocity with respect ground v1 = 3.5 m/s
ball velocity with respect himself v2 = 5.6 m/s
to find out
smallest angle
solution
we know ball velocity with respect field will be
ball velocity = v1 +v2
ball velocity = 3.5 + 5.6 = 9.1m/s
we consider angle that player hit ball is θ
then by as per figure triangle
cosθ =
cosθ =
θ = 51.31
so minimum angle is 180 - 51.31 = 128.69°
Answer:
D. Frequency
Explanation:
The energy of an electromagnetic wave is proportional to frequency, mathematically it is expressed as;
E ∝ f
E = hf
where;
h is Planck's constant = 6.626 x 10⁻³⁴ Js
The equation above can also be expanded to;
where;
c is speed of light = 3 x 10⁸ m/s
λ is the wavelength of the electromagnetic wave
Since the speed of light is constant, we can conclude that the energy of the electromagnetic wave is directly proportional to its frequency and inversely proportional to its wavelength.
Therefore, the correct option for direct proportionality is FREQUENCY