<span>If the swimmer is swimming perpendicular to the current, it will take her 66m / 0.42 m/s = 157.14 seconds to cross the river. At the same time, the current will be taking her downstream at a rate of 0.32 m/s. So, when she reaches the opposite bank, her total downstream distance traveled will have been 0.32*157.14 = 50.28 meters.</span>
Answer:
power, P = 90 hp
Explanation:
It is given that,
Mass of the car, m = 1500 kg
Initial velocity of car, u = 0
Final velocity of car, v = 25 m/s
Time taken, t = 7 s
We need to find the average power delivered by the engine. Work done divided by total time taken is called power delivered by the engine. It is given by :
According to work- energy theorem, the change in kinetic energy of the energy is equal to work done i.e.
P = 66964.28 watts
Since, 1 hp = 746 W
So, P = 89.76 hp
or
P = 90 hp
So, the average power delivered by the engine is 90 hp. Hence, the correct option is (E) " 90 hp".
It occurs when energy is supplied or withdrawn :)
Explanation:
do we can say that the first step is finding the acceleration of the object. We do so by saying F = ma
so a = F/m
a = 500 m/s^2
we now have the time, acceleration and initial velocity.
so we can find the final velocity by using one of newtons equations which is: vf = vi + at
so:
vf = 0 + 500 × 12
vf = 6000
note that our initial velocity was zero since the object was initially at rest.
if you still have any doubt dont hesitate to ask for further help.
Answer: Option d.)
R_eq = (1/R_1 + 1/R_2 + 1/R_3)^-1
Explanation:
Since, there are three resistors connected in parallel, the reciprocal of the total resistance of the resistor combination (R_eq) is obtained by adding the reciprocal of each resistance.
i.e 1/R_eq = (1/R_1 + 1/R_2 + 1/R_3)
So, R_eq = (1/R_1 + 1/R_2 + 1/R_3)^-1
Thus, the total resistance (R_eq) is equal to the inverse of the sum of the reciprocal of each resistance.
