<h2>
Speed of motorboat is 36 km/hr and speed of current is 4 km/hr.</h2>
Explanation:
Let speed of motor boat be m and speed of current be c.
A motorboat traveling with a current can go 160 km in 4 hours.
Distance = 160 km
Time = 4 hours
Speed = m + c
We have
Distance = Speed x Time
160 = (m+c) x 4
m + c = 40 --------------------- eqn 1
Against the current it takes 5 hours to go the same distance.
Distance = 160 km
Time = 5 hours
Speed = m - c
We have
Distance = Speed x Time
160 = (m-c) x 5
m - c = 32 --------------------- eqn 2
eqn 1 + eqn 2
2m = 40 + 32
m = 36 km/hr
Substituting in eqn 1
36 + c = 40
c = 4 km/hr
Speed of motorboat is 36 km/hr and speed of current is 4 km/hr.
Answer
Any force greater 490N
Explanation
The force required just to make an object slide over a rough horizontal surface is any force greater that the static friction which given by;
Given;
Hence;
F = 0.5 x 100 x 9.8
F = 490N.
We will only need the coefficient of kinetic friction if we were asked to find the force required to keep the object moving uniformly. Usually, the force needed to keep an object moving uniformly over a rough surface is lesser that which is needed to start its motion.
In this problem, we were only asked to find the minimum force required to make the object move which we have done.
Answer:
big half like whale is so big
Answer:
3.6*10¹⁰N/C
Explanation:
The formula for Electric field strength is expressed as:
E = kQ/r²
k is the coulombs constant = 9*10^9Nm²/C²
Q is the charge = 1.00×10°C
r is the distance = 0.50m
Substitute the parameters into the formula as shown:
E = kQ/r²
E = 9*10^9(1)/0.5²
E = 9*10^9/0.25
E = 36*10^9
<em>E = 3.6*10¹⁰N/C</em>
<em>Hence the electric field strength is 3.6*10¹⁰N/C </em>
