Answer:
t = 75.4 s
v = 26.9 m/s
Explanation:
Part1 :
v1 = 0 m/s
v2 = 32 m/s
a = 2 m/s2
The time needed to reach the final speed is:
v2 = v1 + a*t
32 = 0 + 2*t
t = 16 s
Part 2:
constant speed of 32 m/s for 53 s
Part 3:
v2 = 32 m/s
v3 = 0 m/s
t = 5 s
The acceleration is negative because the car is stopping:
v3 = v2 + a*t
0 = 32 + a*5
a = - 6.4 m/s
a) The total time the car is in motion is:
total time = 16 + 53 + 6.4 = 75.4 s
b) For the average speed you can calculate the total distance and divide it by the total time for an easier way
Part 1
d = (32+0)/2 * 16 = 256 m
Part 2
d = 32 * 53 = 1696 m
Part 3
d = (32+0)/2 * 5 = 80 m
Average speed:
v = (256 + 1696 + 80)/75.4 = 26.9 m/s
Answer:
Explanation:
Here image distance is fixed .
In the first case if v be image distance
1 / v - 1 / -25 = 1 / .05
1 / v = 1 / .05 - 1 / 25
= 20 - .04 = 19.96
v = .0501 m = 5.01 cm
In the second case
u = 4 ,
1 / v - 1 / - 4 = 1 / .05
1 / v = 20 - 1 / 4 = 19.75
v = .0506 = 5.06 cm
So lens must be moved forward by 5.06 - 5.01 = .05 cm ( away from film )
I think the first question is talking about the ionic compound Sodium sulfide and it’s formula is Na2S.
And for the second question, i’m pretty sure it’d be a positive charge
Answer:
Scalar, a physical quantity that is completely described by its magnitude; examples of scalars are volume, density, speed, energy, mass, and time. Other quantities, such as force and velocity, have both magnitude and direction and are called vectors.
Explanation:
Scalar quantities give a magnitude, while vector quantities give a magnitude and a direction. The answer will be a measurement that does not change, regardless of the direction of action. Displacement is a measure of length in a given direction; distance is the scalar version of displacement. ... Mass is a scalar quantity.
examples of scalar quantities are mass, speed, distance, time, energy, density, volume, temperature, distance, work and so on