Answer:
The strength of the gravitational force between two objects depends on two factors, mass and distance. the force of gravity the masses exert on each other. If one of the masses is doubled, the force of gravity between the objects is doubled. increases, the force of gravity decreases.
Explanation:
Answer:
option (c) is correct
Explanation:
Half life of a substance is the time in which the element becomes half of is initial value.
half life, T = 8 days
Amount remaining, N = 10 % of original value
Let the original value is No.
N = 10% of No
N = 0.1 No
Let the time taken is t and the decay constant is λ.
The relation between the decay constant and the half life is given by
Us the equation of radioactivity
Taking natural log on both the sides, we get
0.08664 t = 2.303
t = 26.6 days
Answer:
2.295 eV
Explanation:
maximum wavelength, λ = 542 nm = 542 x 10^-9 m
The work function of the metal is defined as the minimum amount of energy falling on the metal so that the photo electrons just ejects the surface of metal.
where, h is the Plank's constant and c be the speed of light
h = 6.634 x 10^-34 Js
c = 3 x 10^8 m/s
Wo = 2.295 eV
Thus, the work function of this metal is 2.295 eV.
Answer:
50km/h
Explanation:
Average velocity = change in distance (or distance travelled) divided by/ the change in time (or time taken.)
The change in distance has been given as 100km.
The change in time is 3pm-1pm = 2 hours.
Therefore the average velocity was 100/2 = 50km/h (to the east).
Hope this helped!
Answer: 2700 Joules
Explanation:
Given variables are:
Workdone (w) = ?
Weight of sack (w) = 15N
Time taken (t) = 3 minutes
The standard unit of time is seconds, so convert 3 minutes to seconds
(If 1 minute = 60 seconds
3 minutes = 3 x 60 = 180 seconds)
Recall that work is done is when force is applied on an object over a distance
i.e Workdone = force x distance.
(However, the force acting on the sack of potatoes is weight)
Hence, workdone = weight x time
w = 15N x 180 seconds
w = 2700 J
thus, 2700 joules of work was done.
