Home
Class 11
PHYSICS
A person is standing at -2 location on t...

A person is standing at -2 location on the number line. He runs to and fro from -2 to +5 location 5 times. How much distance has he covered if he comes back to -2 location at the end?
a) 35 units
b) 7 units
c) 30 units
d) 15 units

Text Solution

Verified by Experts

The correct Answer is:
A, B, C
`l=10m, h=8m, mg=200N`
F=200xx(3/10)=60N`
c. Work done by the ladder on the boy is zero.
When the boy is going up because the work is done by the himself.
b.work done against frictioN/Al force,
`W=murS=fl=(-60)xx10`
c. work done by the force insiede the boy is
`W_b=(mgsintheta)xx10`
`=20xx(8/10)`
`=1600J`
Promotional Banner

Similar Questions

Explore conceptually related problems

Area of the triangle formed by the line x+y=3 and angle bisectors of the pair of straight lines x^2-y^2+2y=1 is a. 2 sq units b. 4 sq units c. 6 sq units d. 8 sq units

The equation of the plane with normal 2 hati + hatj -2 hat k and at distance 5 units from the origin is...........

If the work done by a body on application of a constant force is directly proportional to the distance travelled by the body , express this in the form of an equation in two variables and draw the graph of the same by taking the constant force as 5 units. Also read from thte graph the work done when the distance travelled by the body is (1) 2 units (ii) 0 unit .

An equation of a plane parallel to the plane x-2y+2z-5=0 and at a unit distance from the origin is

If the lines 2x - 3y = 5 and 3x - 4y = 7 are the diameters of a circle of area 154 square units, then obtain the equation of the circle.

The principle of 'parallax' in section 2.3.1 is used in the determination of distances of very distant starts. The baseline AB is the line joining the Earth's two locations six months apart in its orbit around the Sun. That is, the baseline is about the diameter of the Earth's orbit = 3xx10^(11)m . However, even the nearest stars are so distant that with such a long baseline, they show parallax only of the order of 1" (second) of arc or so. A parsec is a conventent unit of length on the astronomical scale. It is the distance of an object that will show a parallax of 1" (second of arc) from opposite ends of a baseline equal to the distance from the Earth to the Sun. How much is a parsec in terms of metres ?

A person standing at the junction (crossing) of two straight paths represented by the equations 2x-3y+4=0 and 3x + 4y-5=0 wants to reach the path whose equation is 6x-7y+8=0 in the least time. Find equation of the path that he should follow.

A convex lens of focal length 15 cm and a concave mirror of focal length 30 cm are kept with their optic axis PQ and RS parallel but separated in vertical directiion by 0.6 cm as shown . The distance between the lens and mirror is 30 cm . An upright object AB of height 1.2 cm is placed on the optic axis PQ of the lens at a distance of 20 cm from the lens . if A'B' is the image after refraction from the lens and the reflectiion from the mirror , find the distance of A'B' from the pole of the mirror and obtain its magnification . Also locate positions of A' and B' with respect to the optic axis RS.

A man standing on a moving escalator, completes a certain distance in time t_(1) . If the escalator does not move then man covers this distance in time t_(2) by walking. (i) How much time will he take to cover the same distance if he move on the moving escalator in the same direction ? (ii) How much time will he take to cover the same distance if he move on the moving escalator in the opposite direction ?